And I'm David Greene. We are going into the fourth day of a siege at a popular mall in Nairobi, Kenya. The Somalia-based al-Shabab militant group has claimed responsibility. At least 62 people have been killed.

We had NPR's Gregory Warner on the line earlier. He told us that the military is still battling terrorists inside the mall, but they claim to have made progress. Do these militants still have any hostages in there?

GREGORY WARNER, BYLINE: Apparently not. What we're told by Kenyan authorities, what we've been told by the Kenyan interior minister that there's no hostages left inside. Unfortunately they have been telling us that they're in control of the building for some two days now, so there's some kind of end game going on that we don't know about.

GREENE: Well Greg, you've had a chance to talk to some of the survivors who have gone through this ordeal, and I wonder what sort of stories you're hearing from them.

WARNER: So I met up with this guy, Michael Meyer(ph), he's the dean of a new graduate school of journalism starting here, courtesy of the Aga Khan Foundation. Now he wasn't in Westgate Mall at the time of the attack, but he was telling me about the nephew of his Kenyan colleague, a nine year old boy who had been shot in the hip. And as he's lying, bleeding on the floor of the mall, the terrorist who shot him pointed his weapon at his 15 year old sister and his mother.

MICHAEL MEYER: They demanded that the mother and the sister recite a snatch of the Koran. Being Muslim, they could and did. They were shot anyway, shot down in front of this little boy. Why did you do that? Why did you shoot them, he wailed? And the response from one of the terrorist was: Because they were not wearing the hijab.

GREENE: That is just ghastly. They're saying they shot these women because they were not wearing the traditional Muslim head coverings.

WARNER: That's right.

GREENE: And did this - this little boy; do we know what happened to him?

WARNER: The little boy is now in the hospital.

GREENE: I guess that's just a window into these terrorists and the tactics that they're using, I mean - which just sound horrific.

WARNER: You know, I got a chilling description of one gunman from one young woman, she asked me to not use her voice but said I could tell you her story. She was at a cooking competition - a kids' cooking competition - two men came up and started shooting at the kids, parents. This guy was a dark-skinned guy of about 35 years old. She couldn't say what his nationality was. What she did describe was his face - absolutely calm - and the methodical way that he set his machine gun on their group. She said he knew exactly what he was doing. And, curiously, what he was doing was not trying to kill as many people as possible. There were a number of people hiding out, he could've found them and shot them. He was just going about his work, shooting whoever he shot. It reminds us that, for the terrorists here, it may not have been about the numbers of dead, but about how long this drags on and creating this sense of chaos. Somebody planned, really carefully for this. Now, forth day of the siege, this extended endgame where you can hear the helicopters buzzing overhead. The longer this happens in Nairobi, the more unsettled this entire city is.

GREENE: And Gregory, one piece of news that we've gotten is that the foreign minister of Kenya said that there might be two or three Americans among the militants. Do we know anything more about that?

WARNER: A little bit, I mean, let's remind ourselves that al-Shabab claimed responsibility for this attack because of Kenya's presence in Somalia. Kenya joined the War On Terror in October 2011, al-Shabab has been threatening retribution since then. But there are some people who are wondering if al-Shabab did have some help in this case. Kenya's interior minister has tweeted about the multi-national force that was involved here. Kenya's foreign minister, Amina Mohamed, told PBS News Hour last night that the gunmen included two to three Americans of Somali or Arab origin, very young, perhaps 18 to 19 years old. One from Minnesota, one from somewhere else. Again, this is all just speculation and just scraps of information. The U.S. State Department and the British Foreign Office told me that they're looking into the claims but they can't confirm them.

GREENE: All right. Gregory, I know you'll continue following the story. Thanks a lot.

WARNER: Thanks so much, David.

GREENE: That's NPR's Gregory Warner telling us about the situation at that mall in Nairobi. The military seems to have control of the building but there are still militants inside. Transcript provided by NPR, Copyright NPR.